When you write a book, particularly one that requires several years of research, you tend to encounter a bunch of unexpected information. Sometimes you find things that, if reported, will undoubtedly prompt partisans to demand you explain yourself. For me, this begins that process of explaining, given that one of the major characters in my new book on American Communists, Dupes, is Frank Marshall Davis.

Allegations regarding Davis’s Communism are sure to infuriate the Left because of the influence Davis once had over our president. He was a drinking buddy of Barack Obama’s maternal grandfather, Stanley Dunham, and spent time with young Obama. He turns up in the president’s memoir, Dreams from My Father, shrewdly identified only as “Frank”: “I was intrigued by old Frank, with his books and whiskey breath and the hint of hard-earne